It's not uncommon for the financially more capable spouse to hide assets during a divorce. It's both a measure of their greed, and a sick desire to hurt their former "love."
Likely the best case for hiding assets, followed by trying to eliminate custody was in the Tharp vs. Tharp case, in California. The case had everything - including a smart Court of Appeal bench, who promptly unraveled the whole scheme.
The less financially able spouse should be aware the courts, in financial matters, follow laws enacted legislators who follow the constructs of the well-heeled. As such laws benefiting billionaires often come to pass.
These law are specifically constructed to limit discovery of assets. One example of billionaires getting "urgency legislation" came to pass in 2004 when legislators united to help billionaire Ron Burkle. Legislators gutted one bill to insert language for family court. The law benefiting Ron Burkle, passed in record time.
Check the laws in each state, and if assets are hidden, ask the court to order a forensic accountant, paid for by the spouse most capable.
Extreme measures include, in some cases, fake divorces. Another something to be aware of? Secret dockets.
San Luis Obispo Judge, John Trice, it turns out, had his own kind of secret docket.
Judge Trice, working with the Judicial Council Staff, had an order signed where he paid his ex, (after cheating her of their agreed upon retirement benefits) that the public, thanks to the Judicial Council staff, would never see.